Acoustical aid for deaf persons



June 23, 1925.

J. P. MAXFIELD ACOUSTICAL AID FOR DEAF PERSONS Filed Sept. 2 1921 WHIIIIIIIIP Joseph P Maxfi/a Patented June 23, 1925.

STATES PATENT OFFICE.

UNITED :rosn'rn r. maxrmrn,

comrm, INCORPORATED,

or mrmunn,

or NEW YORK, N. Y., A

NEW JERSEY, ASSIGNOR T0 WESTERN ELECTRIC CORPORATION OF NEW YORK.

ACOUS'lIQAL AID roa' DEAF masons.

Application filed September 28, 1921. 'Serial No. 503,771.

To all whom it may concern:

Be it known that I, JOSEPH a citizen of the'United States,

in the county of 'Essex,

Millburn,

P. MAXFIELD,

State of New Jersey, have invented certain new and useful Improvements in Acoustical Aids for Deaf Persons, of

full, clear, concise, and

which the following is a exact description.

"I' 'This invention relates to a device for improving the hearing of tion is subnormal.

persons whose audi- It has been observed that in some cases of defective hearing,

the persons so affected can more readily distinguish ordinary sounds when there. are present sounds having certain periods-of vibration.

posed vibrations serve,

These superimit seems, to agitate the inner ears and render them more receptive to the sounds which it is desired to hear.

troducing in sounds having, ponents of such It is possible therefore to improve deliberately inof a deaf set The frequency and should be selected to suit the individual. Suchsounds may or may not be within the audible range of the personemploylng the device; a

An objeiit of the invention is to provide in order to make them more receptive to means for agitating the organs of hearing sounds which it is desired to hear.

Other objects will hereinafter appear.

Referring to the drawings: Fig. 1 represents a binaural system embodying the invention.

. Fig. 2 represents another method of introduc'ing the auxiliary sounds.

In general the invention consists in providing microphones inductively connected to the input side nected to the output side, receiver circuit for introducing in the reof amplifiers, receivers conand means in the ceivers auxiliary sounds:

In Fig. 1, two microphones 4 and 5 are connected in series with batteries 6 and 7 and the primary windings of induction coils 8 and 9 respectively.

of the induction coils 8 to the terminals of which in turn are circuits Secondary windings and 9 are connected the resistances 10 and 11 bridged across the input of two vacuum tube amplifiers 12 and 13 having the usual heated cathodes 14 and 15, control electro des 16 and 17, and

residing at fiers, and

anodes 18 and 19. The temperature of the filaments and consequently the output of the amplifiers can be readily adjusted by means of rheostats 20 and '21 located in the filament circuits. The output circuits of the amplifiers 12 and 13 are connected respectively to primary windings of transformers 22 and 23. The secondary windings'of these transformers are connected through the secondary windings of transformer 26 to receivers 24 and 25. Across the primary of transformer 26 is connected a source of varying current 27 in any convenient form such as a vacuum tube oscillator. The frequency of the oscillator may be adjusted in any well known manner to the frequency most advantageous for exciting the ears of the person employing the system.

In Fig. 2 the source 27, in series with a condenser 28, is bridged across receivers 24: and 25 in series.

Although a binaural system for deaf persons has been chosen to illustrate the invention, it is. obvious that the invention may be applied to systems designed for one ear only. Again, the system may involve the excitation of the sense of hearing without the use of head receivers, as in cases where the deaf person may be located within the range of influence of the exciting energy. The specific form which the invention may take is dependent upon the character of the deafness and the frequencies of the sounds or energy required to stimulate the'sense of hearing of the person using it.

What is claimed is:

1. The method of improving the hearing of a deaf person, which consists in generating continuous vibrations, applying said vibrations to the patient simultaneously with the sound vibrations to be heard, and adjusting the frequency of the continuously generated vibrations to suit the individual case.

2'. In a binaural system for enabling deaf persons to hear, a pair of microphones, amplifiers associated with said microphones, a pair of receivers associated with said amplicommon means connected between each receiver and each amplifier for introducing a varying current in the receivers.

3; In a system for enabling deaf persons to hear, a pair of microphones, an amplifier associated with eachof said microphones, a air of receivers associated with said ampliers, and means connected between each rethe two cars of the patient, and simultaneously applying to the two ears continuous 10 vibration of such frequency as to aid the patient to hear said sounds.

In Witness whereof, I hereunto subscribe ngylname this 24th day of September A. D., 1 2

JOSEPH P. MAXFIELD. 

